tredecillion

1896: Frank H. Hall, The Werner Arithmetic, Oral and Written, Book Two, Parts I and II

The names of the periods above trillion are as follows [...] 15th, tredecillion [...]

1946CE: United States Department of Commerce, The United States Department of Commerce: How it serves you on land and sea and in the air, U. S. Government Printing Office (1946)

3 quindecillion, 657 quattuordecillion, 262 tredecillion; which is to say the figures 3,657,262 followed by 42 ciphers. Operators of the key punch machines transfer a code symbol from the Census [...].

1994CE: National Council of Teachers of Mathematics, The Arithmetic Teacher, National Council of Teachers of Mathematics (1994)